The feature, currently available only in Chrome, automatically uploads the picture, inserts it into your email where you want it, and allows you to resize it.
Gmail has long allowed you to drag-and-drop images from other browser windows into emails, but this added links to the images, rather than actually attaching them.
This is a pretty minor tweak, but a handy one.
Webmail is one area in which Google has struggled to overtake its online rivals, Yahoo and Microsoft. Yahoo remains the dominant provider of webmail service, which is a great anchor for keeping users coming back to the site. Constantly improving Gmail is a good way for Google to keep eating away at Yahoo’s user base.